Latest news

Determinants of pedestrian mediolateral foot placement in walking on laterally-oscillating structures
2024-08-15

Walking requires the integration of sensory information from different sensory modalities. Previously, it has been shown that when walking on laterally-oscillating structures, mediolateral foot placement depends on the mediolateral velocity of the centre of mass at the instance of foot placement. However, it was not known how the ground conditions and the visual environment affect the pedestrian stepping behaviour in this case. This important issue needs to be addressed as the stepping behaviour determines the magnitude of the lateral forces exerted by pedestrians on structures and is therefore critical for the assessment of lateral structural stability.

Closed-form long-term solutions of calibrated and generalised Macdonald’s model for pedestrian-induced lateral forces
2024-05-19

The closed form solutions of the long-term average pedestrian lateral forces generated from the inverted pendulum pedestrian model (IPM) originally proposed by John H.G. Macdonald were derived by Allan McRobie. Having calibrated and generalised the IPM, we have now derived the closed-form solutions of the long-term average pedestrian lateral forces based on the same framework.

Calibration of the inverted pendulum pedestrian model for laterally-oscillating structures based on stepping behaviour
2023-11-10

A biomechanically-inspired inverted pendulum pedestrian model (IPM) was first introduced to the field of structural engineering by John H.G. Macdonald in 2009 [1]. The original IPM has been shown to qualitativelly capture pedestrian behaviour on laterally-oscillating structres, including the structural excitation mechanism. However, to make it suitable for use in engineering applications, it had to be reconciled with empirical observations. This task has been accomplished in our recent paper.

Resonance curve - the case of pedestrian laoding on structures
2022-12-06

Resonance is one of fundamental concepts in structural dynamics. In simple terms, it occurs if a periodic force is applied to the (structural) system at or near one of its natural frequencies. This leads to the amplification of the response relative to the case when no resonance occurs. The consequences of this phenomenon can be severe, from accelerated degradation of the structure, lack of fitness for its purpose, to the catastrophic failure. Therefore, understanding this phenomenon is of critical importance to any engineer.

Dynamic performance verification of the Rędziński Bridge using portable camera-based vibration monitoring systems
2022-12-06

Monitoring evolving patterns of the dynamic behaviour of long-span bridges is a critical task in their maintenance and management. For the bridges lacking permanent monitoring systems, ad hoc testing campaigns are sometimes implemented. These are typically costly and utilise wired instrumentation systems requiring a direct contact with the structure, hence they can create risks to the involved personnel and equipment. An alternative solution is explored in our newest paper, reporting successful attempts at obtaining modal damping based on data from optical motion capture systems.

A methodological approach towards evaluating structural damage severity using 1D CNNs
2021-10-26

Monitoring civil infrastructure simplifies and improves reliability of decision-making in asset management. This task is increasingly important in established economies, in which engineering infrastructure has aged thus becoming exposed to various risks affecting structural integrity. In the latest paper, driven by our friends at the University of Leeds, we have explored the performance of 1D CNN in structural damage detection based on numerical simulations.